1. Field of the Invention
A drift control device for use with a small boat adrift to effect the direction and drift speed of the small boat against the forces of wind and current.
2. Description of the Prior Art
Often, fishermen fish from a boat while adrift.
A boat adrift relatively close to the shore-line or river bank while fishing will generally cause the small boat to veer into the direction of the wind commonly referred to as weather-cocking. Weather-cocking can force the boat toward or away from the shore-line or river bank.
The degree of weathercocking depends on such various factors as wind angle, the shape and profile of the small boat's hull, the small boat's load distribution, the amount of hull side-slip which is governed by wind force and hull draft, and the depth of the water in which it is being operated.
Various devices have been invented to provide directional control accounting for the current and wind forces on a water craft. Pertinent examples of the prior art are disclosed below.
U.S. Pat. No. 4,889,006 shows a kayak steering apparatus for controlling kayak weathercocking during operation in side wind conditions. An elastomeric line in tension and a non-elastic control line are each attached to opposite side arms of a vertically pivoting rotor which is mounted to the stern of a kayak with the rotor further being connected to a rudder. A kayak operator can, by hand, pull on or release the control line which acts in combination with tension in the elastomeric line to turn the rotor and thereby set rudder angular position. For setting vertical depth, the rudder is connected to the rotor by a pin which allows the rudder to pivot about a generally horizontal axis. Depth adjustment is also hand controllable by pulling or releasing a line connected to the upper portion of the rudder at a location offset from the horizontal axis defined by the pivoting pin.
U.S. Pat. No. 3,990,385 teaches a self-steering mechanism for a sailboat comprising the combination of a wind vane mounted for rotation about a substantially vertical axis coupled to a differential hydraulic pressure regulator. A hydraulic motor and pump is provided having a pressure regulator located between the motor and pump. The arrangement is such that the hydraulic pump, which can be driven by movement of the vessel through the water, the wind or other suitable sources, provides the hydraulic pressure required to operate the hydraulic motor, which motor is controlled by a differential hydraulic pressure regulator that is mechanically coupled to the wind vane. In this fashion the sailboat rudder which is coupled to the hydraulic motor can be controlled relative to the angle of attack of the wind against the wind vane.
U.S. Pat. No. 4,203,380 discloses a rudder assembly for a boat including a rudder shaft rotatably mounted to a boat and inclined downwardly and rearwardly. A rudder blade is attached to the lower end of the shaft and a plate is attached to the lower edge of the blade. The inclined shaft permits control of the rudder assembly from the central portion of the boat while allowing the rudder blade to be disposed near the stern for improved control. The plate provides for increasing resistance to the flow of water as the rudder blade is moved to the left or right of the straight-on position.
U.S. Pat. No. 4,327,657 describes a self-steering system to maintain a sailing craft on a preselected heading relative to the apparent wind. An oar member which forms a hydrodynamic servo is mounted on a center body for rotational motion. Also supported on the center body above the oar member is a wind vane which is mounted for rotational adjustment and for pivotal motion substantially normal to its rotational axis. The center body is pivotally supported on the transom of the sailing craft for motion about an axis approximately parallel to the longitudinal center line of the boat. The wind vane is coupled to the oar member such that when the heading of the sailing craft changes relative to the apparent wind, the wind vane is pivotally driven sidewise by the wind and through its linkage thereto rotatably drives the oar member. Such rotatable motion of the oar member from a predetermined neutral position results in sidewise water forces thereon which pendulously drive the oar member sidewise and along with it rotate the center body and the vane base. The center body is coupled through a suitable linkage to the steering control of the sailing craft such that the sidewise pendulous motion of the oar causes the steering control to drive the rudder of the sailing craft in a direction such as to maintain the sailing craft on the preselected heading relative to apparent wind.
U.S. Pat. No. 4,348,973 relates to a self steering apparatus for a boat comprising a motion transfer apparatus for converting pivotal movement of a wind vane into rotational movement of a rudder. The latter is located in a support which is pivotable about the fore and aft axis of the boat. A rotatable connection is provided between a control arm arranged for movement with the vane and a rudder arm arranged for movement with the rudder, such that, when movement of the vane is initiated, there is resultant movement of the rudder arm about the fore and aft axis with movement of the rudder about its axis, and subsequent movement by the water of the rudder support about the fore and aft axis, and movement of the control arm is effected on initial movement of the rudder about its axis but does not result from movement of the rudder support about the fore and aft axis. Lines transmit movement of the rudder support about the fore and aft axis to the main rudder or tiller of the boat.
Additional examples of the prior art are found in U.S. Pat. No. 4,372,241; U.S. Pat. No. 4,711,192; U.S. Pat. No. 7,430,976; U.S. Pat. No. 7,775,173 and U.S. Pat. No. 8,151,724.